With the demand for high image resolution, high refresh rate and 3D technology development, the development of high mobility TFT material is crucial. Low temperature polycrystalline silicon may have mobility up to 100 cm2/Vs, but its manufacturing cost is high and its uniformity still need to be further improved in the production of large-size backplanes. Oxide channel materials more studied currently comprise indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO) and other materials with the mobility of 10˜30 cm2/Vs around, and need to be further improved in practical applications.
In the oxide TFT industry, the quantity of carriers in the channel is generally increased by doping metal ions in the oxide channel layer, to achieve the purpose of increasing TFT mobility. Wherein, the doping ions mostly are ions of large orbital radius with weak metal ion-oxygen bond energy, such as In3+, Sn4+, etc. However, because doping ions have weak bond energy with oxygen, they easily cause oxygen vacancies and oxygen dangling bonds, and finally affect the stability of oxide TFT.